Why Models By creating models about migration geographers

Why Models? By creating models about migration, geographers can describe and predict how people will move from place to place. These models allow governmental leaders, to plan how to allocate resources and create public policies that will affect people who migrate into or out of different places on Earth.

The Takeaway! Human geographers collect and analyze statistics to better understand patterns and phenomena on Earth. Human geographers construct models to relay information about patterns and phenomena on Earth. The gravity model of migration is one tool for understanding and predicting migration patterns

“There must be a force pulling the apple to Earth!” Sir Isaac Newton determined that the force of gravity between any two objects in the universe depends on the mass (population) of the two objects and the distance between them. Human geographers hypothesize that migrants are more likely to move to large cities that are not too far from their place of origin than small cities that are farther away.

One benefit of the gravity model of migration is that it is fairly simple and can be easily used to compare the likelihood of migration between different pairs of locations.

There are many variables that the gravity model does not address Differences in: Culture Economy Political situation of each country Individual preferences and values Distance and population may not be the most important determining factors. **One benefit of the gravity model of migration is that it is fairly simple and can be easily used to compare the likelihood of migration between different pairs of locations.

e r o m The there le p o re e o p m e h t t a , h e t r a ts n a r g i m er t im n e will The Gravity Model Any model that expresses interaction between two places as a function of: -the size of the two places (population) -the distance between them

Here’s the MATH! Human geographers use a mathematical formula to predict the likelihood of migration between places. Expressed mathematically, the gravity model of migration looks like this: (Population of Location A x Population of Location B) M (Migration)= 2 (Distance between Location A and Location B)

The Gravity Model “In Action”

Human Spatial Behavior

I. Mobility a. Circulation: No relocation of residence. • Temporary use of space b. Migration: Leaving the home territory and finding residence in a new location • Refugees who are forced out of their homes

II. Activity Space a. What effects our activity space? 1. Age 2. The means of mobility available (the ability to travel) 3. Demands in their daily activities (do you have to travel) b. Territoriality: Emotional attachment to and defense of home ground c. Personal space: The zone of privacy and separation from others our culture or physical circumstances require and permit.

Activity Space: Area within which we typically move freely on our rounds of regular daily affairs. Age A small child’s daily travel v. a high school student’s daily travel Adult’s responsible for the household v. Elderly Which age (or stage in life) do you think is the most mobile? **consider all factors**

Space-Time Prism AKA: Time-geography The volume of space and length of time within which our activities must be defined. Critical distance: The distance beyond which cost, effort, and means strongly influence our willingness to travel Think Distance Decay!

IV. Information Flows a. Individual communication field: Determined by individual spatial patterns of communication. • b. c. Size and shape are defined by the individual’s contacts Mass communication: Transmission of information in a one way flow. • Few transmitters, many receivers • No spatial restrictions • Hierarchies in the market size requirements (national v. local news) • There must be an audience Role of technology?

V. Information & Perception a. Place perception: The awareness we have (as individuals) of home and distant places and the beliefs we hold about them. b. Directional bias: Have greater knowledge of places in some directions than in others. a. Barriers to information *Is Coral Gables better than Kendall? Doral or Liberty City in Overtown? c. natural hazards: Elements, processes, or events in the environment that can cause harm to humans.

Natural Hazards Elements, processes, or events in the environment that can cause harm to humans. Why Stay? 1. Hazardous events are relatively rare 2. Residents usually resettle 3. Hazardous areas are usually coastal 4. Hazardous areas are often residentially desirable 5. With time, the memory of hazardous events fades

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